关键词: 涤纶工业丝, 活化油剂, 力学性能, 热收缩性能, 结晶度, 取向

Abstract: The activated polyester industrial yarn is a new type of industrial yarn. It can form good adhesion with rubber, PVC and other polymer matrices due to the reactive activating oiling agent attached to its surface. The original composite molding process of "spinning oiling-predipping-RFL dipping-rubber compounding" can be simplified into "activated oiling-RFL dipping-rubber compounding" because of the activated filaments. This technology can prepare polyester fabric reinforced composites with light weight, deformability, high strength, high modulus and good dimensional stability, which can be widely used in automotive industry, construction engineering and other fields.
Activating oil agents play an important role in the preparation of activated polyester industrial yarns. As an important auxiliary agent to endow surface activity of polyester industrial yarns, the activating oiling agent is usually dynamically oiled through nozzles or tankers after fiber preparation. When the activating oil agent contains a humidity sensitive group, it is generally necessary to dry the oiled fibers in order to prevent excess water molecules from interfering the activation reaction after the unsealing section of the activating oiling agent. At present, there is little research on the influence of the activating oiling agent and drying treatment on the original properties of polyester industrial yarns. For this reason, three kinds of common polyester industrial yarns (general high strength GHT, high modulus low shrinkage HMLS and high strength ultra-low shrinkage SLS) were chosen as the raw materials. The yarns were treated with activating oil agents, and dried at room temperature or 75 ℃. The effects of activating oil agents and drying conditions on the linear density, mechanical properties, thermal shrinkage properties, sonic orientation and crystallinity of polyester industrial yarns were thus investigated. The experimental results show that the linear density and crystallinity of the three polyester industrial yarns increase slightly after drying treatment, while the mechanical properties, thermal shrinkage properties, sonic orientation factor and sonic modulus all decrease, especially for the Young's modulus of HMLS. After oiling treatment, the linear density of the three yarns increases, but the breaking strength, Young's modulus and thermal shrinkage decrease, and the elongation at break and crystallinity have little change. The sonic orientation factor and sonic modulus of GHT and HMLS are higher after oil treatment. Compared with the other two yarns, SLS after being oiled and dried at 75 ℃ has less mechanical strength and modulus loss, greater reduction in thermal shrinkage ratio, better dimensional stability, and higher crystallinity, which indicates that SLS is more suitable for activation modification among polyester industrial yarns.
In this paper, the effects of activating oil agents and different drying conditions on the performance of GHT, HMLS and SLS polyester industrial yarns provide a new idea for the selection of polyester industrial yarns and the activation of polyester industrial yarn treatment process, and also provide a reference for the subsequent application of enhanced composite materials for polyester industrial yarns. 

Key words: polyester industrial yarn, activating oil, mechanical properties, thermal shrinkage properties, crystallinity, orientation